Cleanrooms are controlled environments with low levels of contaminants such as dust, airborne microbes, aerosol particles, and chemical vapors. The aim is to minimize the introduction, generation, retention and circulation of particulate matter inside the room. Cleanrooms are used extensively in industries like semiconductor manufacturing, biotechnology, pharmaceuticals, aerospace and healthcare where dust, microbes and particles can severely affect product quality.
The International Organization for Standardization (ISO) has established standards for classifying cleanrooms based on the number of particles permitted per volume of air. These ISO standards help set requirements for constructing and operating cleanrooms for different purposes. The ISO 14644-1 standard classifies cleanrooms into 9 grades from ISO Class 1 to ISO Class 9, with ISO 1 having the lowest levels of contaminants.
The purpose of grading cleanrooms is to set stringent air quality standards needed for processes and products that demand ultraclean environments. Cleanroom grades provide a way to control viable and non-viable particles that can affect manufacturing processes and quality control.
What is ISO 5?
ISO 5 is an air cleanliness classification defined by the ISO 14644-1 standard. It is one of the cleanroom classifications established by the International Organization for Standardization (ISO) to define acceptable concentration limits for airborne particles in cleanrooms and other controlled environments.
The ISO 5 classification specifies that for every cubic meter of air in the cleanroom, there must be no more than 100 particles larger than 0.5 microns. This strict particle count makes ISO 5 suitable for industries with extremely high cleanliness requirements like pharmaceutical manufacturing, medical device assembly, and semiconductor fabrication 1.
In addition to particle count limits, ISO 5 cleanrooms must meet requirements for humidity, temperature, air changes per hour, airflow patterns and pressurization. Construction materials like walls, floors, doors and filters must be designed to minimize particle generation. Personnel must follow strict gowning procedures and operations must be carefully controlled to maintain contamination-free conditions.
Particle Count Testing
Particle count testing is a critical part of certifying and maintaining cleanrooms at the ISO 5 classification level. Particle counters are used to measure the concentration of airborne particles inside the cleanroom environment. According to How to Test Your Cleanroom Classification, particle count tests must be performed annually for cleanrooms ISO Class 6 and above, or biannually for ISO Class 5 and below.
To be certified as an ISO 5 cleanroom, particle concentration measurements must meet strict limits. The maximum permissible particle concentration is 3,520 particles per cubic meter for particles ≥0.1 μm, and 20 particles per cubic meter for particles ≥0.5 μm. Handheld particle counters are commonly used to sample various locations in the cleanroom and ensure particulate levels are within specified limits.
According to How to Select the Best Cleanroom Particle Counter, handheld counters are useful for identifying major particle sources during testing. However, more advanced automated counters installed in the HVAC system provide continuous monitoring and protect against transient spikes in contamination.
Repeated particle count testing is necessary to audit and recertify ISO 5 cleanrooms over time. Facilities must implement rigorous contamination control procedures to continually meet the strict particulate concentration limits at this highest air cleanliness level.
Construction Requirements
Constructing an ISO 5 cleanroom requires careful planning and strict adherence to standards. The main requirements focus on HVAC systems, materials, garments, and cleaning procedures.
The HVAC system is critical for maintaining the ISO 5 air quality. The system must provide HEPA-filtered air that exchanges the entire cleanroom air volume at least 30-50 times per hour. Temperature and humidity must also stay within tight ranges. AVAC engineered air handling systems are commonly used.
All surfaces and furnishings must be smooth and non-shedding. Stainless steel is a common material. Floors are typically coved and vinyl. Cleanroom garments prevent contamination from people. Multiple gowning layers, hair/shoe covers, gloves, and face masks are required.
Rigorous cleaning procedures remove particles. Surfaces are disinfected daily or more often. Cleaning tools must not shed particles. Only filtered vacuum cleaners are permitted. Staff must follow strict gowning/degowning protocols.
Common ISO 5 Cleanroom Uses
ISO 5 cleanrooms are commonly used in the following industries that require extremely clean and controlled environments:
Microelectronics – Semiconductor and microchip fabrication facilities require ISO 5 cleanrooms for photolithography and other processes where even microscopic particles could ruin products.[1]
Pharmaceuticals – Medicines and injectables are manufactured in ISO 5 cleanrooms to prevent contamination and ensure patient safety.[2]
Medical Devices – Medical implants, prosthetics, and other devices are made in ISO 5 cleanrooms prior to sterilization and packaging to reduce risk of infection.[3]
Aerospace – Sensitive aerospace components and optics are produced in ISO 5 cleanrooms to prevent defects.
Maintaining stringent cleanliness is critical in these industries where product quality and human health rely on the absence of particles and pathogens.
[1] https://www.americancleanrooms.com/what-is-an-iso-5-cleanroom-classification/
[2] https://www.soscleanroom.com/blog/industries-that-use-cleanrooms/
[3] https://www.duroair.com/blog/5-industries-fueling-the-growth-of-iso-clean-rooms
Maintaining ISO 5 Cleanrooms
Maintaining an ISO 5 cleanroom requires diligent daily cleaning and air filtration to meet the strict particle count requirements. According to Gotopac, daily cleaning involves wiping down all surfaces with 70% isopropyl alcohol to remove contaminants. Floors should be mopped daily as well. Garments such as cleanroom suits, gloves, hoods and boots must be changed frequently to minimize particle shedding. The recommended garment change schedule is 2-3 times per week.
Air filtration is critical in an ISO 5 cleanroom. The room must have 300-480 air changes per hour using HEPA filters to maintain air purity. HEPA filters should be checked regularly for leaks or damage and replaced at least annually. Airflow and pressure differentials should be monitored continuously to ensure proper ventilation. Particle count testing should be conducted routinely, such as daily or weekly, to validate that particle levels remain below the ISO 5 limit of ≤3,520 particles/m3 at ≥0.5 μm diameter.
According to American Cleanrooms, vigilant maintenance and monitoring processes are required to preserve the integrity of an ISO 5 cleanroom environment.
Costs of ISO 5 Cleanrooms
ISO 5 cleanrooms are expensive to construct and operate due to the extremely stringent requirements needed to achieve this cleanroom classification. According to Cleanroom cost estimator, construction costs range from $190-$215 per square foot for an ISO 5 cleanroom.
Major costs include the HVAC system, specialized filtration, monitoring systems, cleaning procedures, facility materials, and cleanroom garments. HEPA filters must be frequently changed, driving up maintenance expenses. Cleanroom garments, gloves, masks and boots for personnel also contribute to costs.
Certification and re-certification via particle counting is mandatory for ISO 5 cleanrooms, which can cost thousands of dollars each time. Yearly operating costs for energy, cleaning/sanitization, consumables and more frequently exceed construction expenses.
Overall, owners should budget around $200/square foot for ISO 5 construction, and plan for significant ongoing costs to operate and re-certify these ultra clean environments. details typical price ranges and considerations when estimating ISO 5 cleanroom expenses.
Advantages of ISO 5
ISO 5 cleanrooms provide a highly controlled environment with extremely low particulates. According to ISO Class 5 Cleanrooms | Fed-Std 209E …, ISO 5 cleanrooms must maintain particulate levels at or below 3,520 particles per cubic meter (0.1 microns or larger). This rigorous standard ensures almost complete elimination of particulates that could contaminate sensitive processes and products.
The tightly regulated ISO 5 environment allows companies to manufacture advanced technologies and life science products with little risk of defects or errors caused by airborne particles. Sensitive electronics, pharmaceuticals, and medical devices can be assembled in ISO 5 cleanrooms with high confidence in quality control. The high level of air filtration also helps prevent biological or chemical cross-contamination.
Overall, the extremely low particulates and precise standards of ISO 5 cleanrooms provide major quality assurance benefits for companies dealing with sensitive or high-precision products. This allows them to guarantee a contamination-free manufacturing environment.
Disadvantages of ISO 5
While ISO 5 cleanrooms provide critical environments for sensitive manufacturing and research, they also come with some drawbacks. One of the biggest disadvantages of ISO 5 cleanrooms is the high cost required to build and operate them. Constructing an ISO 5 space requires specialized materials, rigorous HVAC systems, and intricate monitoring tools that drive up expenses compared to lower-grade cleanrooms. According to this article, clean zones that provide ISO 5 conditions are more expensive than those rated ISO 8 or below.
In addition to high construction costs, ISO 5 cleanrooms require substantial energy to maintain constant temperature, humidity, and air filtration. The extensive HVAC systems operating 24/7 consume large amounts of electricity to preserve the ultra-clean environment. Facilities must budget higher utility bills for ISO 5 cleanrooms compared to more relaxed standards.
Maintaining an ISO 5 space also demands strict training and preparation for anyone entering the cleanroom. Workers must master gowning protocols and contamination control processes before access is granted. Companies must invest in comprehensive training programs and routinely assess employee competency. The more rigorous requirements for access place extra burdens on staff and facilities.
While indispensable for certain manufacturing and scientific work, the disadvantages of expense, energy demands, and training requirements make ISO 5 cleanrooms impractical for less sensitive applications. Facilities must determine if the higher costs and complexity of ISO 5 are justified based on their specific needs.
The Future of ISO 5 Cleanrooms
As technology continues to advance, ISO 5 cleanrooms will likely see innovations in areas like automation, modular construction, and sustainability. Automation can help improve efficiency and reduce contamination risks by minimizing human contact in cleanroom processes. Robotic arms and automated material handling systems are already being adopted in some ISO 5 cleanrooms.
Modular construction techniques using prefabricated components allow for faster and more flexible cleanroom design. This makes it easier to modify or expand ISO 5 cleanrooms as needs change. Modular cleanrooms also enable companies to construct state-of-the-art facilities faster and cheaper compared to traditional construction.
Sustainability will also become more important for ISO 5 cleanrooms going forward. Strategies like LED lighting, air recycling systems, and low-flow cleanroom garments can help reduce energy and resource consumption. ISO 5 cleanroom operators will continue finding ways to minimize their environmental footprint while maintaining contamination control.
With their high filtration and stringent protocols, ISO 5 cleanrooms will remain essential for industries like pharmaceuticals, microelectronics, and medical devices. But expect continuous innovation in ISO 5 cleanroom design, construction, and operation to improve quality, efficiency, and sustainability.
